1. Field of the Invention
The present invention concerns a method for the extension of the display range of 2D images of an object region of the type wherein first 2D or 3D image data of a larger object region are provided, at least one set of additional 2D image data of a smaller object region is obtained that lies within the larger object region, and the additional image data are displayed in combination with the 2D image.
2. Description of the Prior Art
In surgical interventions nowadays, compact image capture systems such as mobile X-ray devices, ultrasound devices, or endoscopes/laparoscopes are often used. These modalities, however, offer only a limited field of view for image capture. For the surgeon, however, it is desirable to be able to view the local situation in the treatment area in a larger context as well.
Different options are known in which 3D image data of the body are recorded at some larger time previous to the surgical intervention, for instance using X-rays, X-ray computed tomography, or magnetic resonance tomography, in order to be able to visualize the spatial context during the intervention using this 3D image data. A distinction can be made between two variants. In the first variant, a current local display of the treatment area, which has been recorded with the mobile image capture modality, appears on a main monitor. On a second monitor, for comparison, there appears the overall view from the previously recorded 3D image data. In the second variant, there is a superimposition or merging of images. The current local view, for instance an endoscope view, is directly superimposed on the overall view from the earlier examination. Both views can be appropriately transparent and shown in complementary colors. An example of such a variant is described in DE 102 10 646 A1, which describes a superimposition of image data from a 3D image capture modality onto the 2D fluoroscopic imaging of the examination region. The projection geometry of the 2D fluoroscopic image is taken into account in the superimposition, just as in another embodiment of the process the depth from which the structures detectable primarily in the 2D fluoroscopic image originate is also taken into account.